Grease lubrication has been widely used as a lubrication method for rolling bearing. The grease lubrication requires periodical grease replenishment because the grease is quickly deteriorated under such environments as high-temperature, high-speed rotation, and high load conditions, and shortened in service life. In this connection, there has been provided a rolling bearing assembly which is equipped with a lubrication device capable of continuously supplying base oil of the grease to a rolling bearing (see, for example, Patent Literature 1).
FIG. 7 is a sectional view showing an essential part of the rolling bearing assembly equipped with the lubrication device. In the figure, the rolling bearing 100 is an angular contact ball bearing which includes a plurality of balls 103 as rolling elements interposed between a raceway 101a of an inner ring 101 and a raceway 102a of an outer ring 102 and retained by a cage 104 as circumferentially arranged at predetermined intervals.
The cage 104 includes a plurality of cage bar portions 106 extending between a pair of annular portions 105, respective pairs of cage bar portions 106 defining respective pockets 107 therebetween. The pockets retain the balls 103 and are circumferentially arranged at predetermined intervals.
A lubrication device 200 includes an annular grease reservoir member 201 abutting on one end face of the outer ring 102 of the rolling bearing 100, and an annular minute space 203 defined between an inner periphery of the outer ring 102 and an annular gap forming portion 202 projecting from one end of the grease reservoir member 201 such that grease G is introduced into the minute space 203. A distal end of the gap forming portion 202 is spaced close to the ball 103.
The cage 104 includes a guided surface 108 defined by an outer periphery of one (the right-hand one as seen in FIG. 2) of the paired annular portions 105. The cage 104 is guided in rotation by allowing the guided surface 108 thereof to make sliding contact with a guiding surface 109 defined by the inner periphery of the outer ring 102.
In the above rolling bearing assembly, the base oil of the grease G stored in the grease reservoir member 201 infiltrates and migrates into a place in the proximity of the raceway 102a of the outer ring 102 by capillary action of a thickener contained in the grease G, thereby supplying the base oil to the race way 102a of the outer ring 102.
[Citation List]
[Patent Literature]
[Patent Literature 1] Japanese Unexamined Patent Publication No. 2005-180629